The application of variants of the Thousand Grain Mass method and of the Count and Weigh method for assessing weight losses caused by insects during the storage of 1aize, paddy rice and sorghum grain in villages of Côte d'Ivoire and Central African Republic bas allowed a new improvenent in the second method, which enables a good correlation of loss level with a biologically unbiased criterion. In this study realized under field laboratory conditions as also regarding the grain variability and the sampling pattern required, the second method proves to be by far the most practical and accurate. The implications of these results are discussed in the view of a field application for loss assessment programs.